Remote reading gyromagnetic compass



l Jan. 21, 1941. M. F. BATES REMOTE READING GYRoMAGNETIc cormss Filed Deo. 17, 1958 2 Sheets-Sheet l 60 /WwU/c Campi/M470 Jan. 21, 1941." M F. BATES REMOTE READING GYROMAGNETIC COMFASS v 2 Sheets-Sheet 2 Fiied Dec. 17, 193B INVENTOR @ogg/15 E BATES M TToRNEY.

. 'Patented Jan. 2l, 1941 PATENT orrics REMOTE READING ESYROMAGNE-TIC Sperry Grroleose Company. Ine.. Brooklyn,

MY., a corporation of NewY ork `Application nmmberu, 193s, 'seni Nn. mass f s owns (ci. :is-m) This invention relates to the art oi transmitting to a distance the readings or position ot a sensitive instrument, such as a directional gyroscope or gyromagnetic compass. The invention has especial application to the last `named instrument, v since it is desirable to locate the c compass at a. point on the ship or airplane least subject to disturbances of the magnetic element, while it is desirable to have the o! the l@ compass visible on the instrument panel.

For the sake of illustration, lI have shown my invention as applied to a gyroinagnetic compass oi the type shown in the patent and copending application of Leslie F. carter, No. 2,091,964, dated w September '1, 1938, and Serial No. 233,757, iiled October 7, 1938, respectively.

Another object of the invention is to provide a follow-up system for an instrument of this type which is extremely sensitive and "accurate and to yet not subject to hunting.

Further objects of the invention will appear from thefollowing description.`

Referring to the drawings, showing one form my invention may assume,

Fig. 1 is a vertical section, partly in elevation, of a gyromagnetic unit with follow-up and remote control device.

. 2 is an enlarged detail, partly in section, of a portion of Fig. 1, showing the follow-up servoinotor.

Fig.'3 is a sectional view taken at right angles to Fig. 2.

Fig. 4 is a vertical section of the upper portion oi the gyromagnetic compass, showing the diiierential air flow pick-oi! device. liig.5isasideelevation,partlyinsection,oi the driven element ci the friction drive servomotor.

Fiend isatopviewofthecut-oi'i plateiorming the portion ci the dinerential sir pick-oi! device so which is complementaryto the pbrt shown in Fig. 4.

As stated above, my invention is shown as applied tothe form o! c compass shown inthecarterpatentsndapplicatimvhichisor ilitheairbornetypehavingtheverticslringi supportedinuppersndlowersphericalairbearings2and2',tbestatlonaryportionsotwhich comprisecupslandl'. Acylindricalcompass cardisshownassmroimdingtbeverticslrlnm Therotorlisshownindottedlineswithintbc rotorbearinscasinglthelatterbeingmounted foroscillationaboutahorisontalaxisinspherlcsl airbearingslandl. Themalneticelement v/ is shown at 1, being rotatably. mounted on air inthebottomoftbecasinslandthb controls the position of the gyromagnetic in azimuth by means such as described in the aforesaid patent and application. The box contains a compensator for the magnetic element.

In order to secure remote control, the upper s spherical bearing housing 3 is shown as rotatably mounted, being secured to a conical shaped stem l as by means of set screw 9. Also rotatable with said bearing I' is the channel member Il Y which carries the slotted ports Il and ii' form- 10 ing one portion oi the diilerential air ilow pickoi! device by which I control the iollow-up servo motor I2. Air is preferred to electricity in order to keep all D. C. electrical circuits as tar away from the magnet 'l as possible. The slots il are 15 generally made radial and comparatively narrow, so that a large diilerence in the air flow is produced by small relative rotation o! the semicircular cut-oi! plate i3 carried by the vertical ring l ofthe gyrosoope. Slots il, Il' and the 20 edges oi plate Il form the pick-oil or controller for, the iollow-up system I employ to actuate the transmitter I8 of the remote control system.

The air pressure employed tooperate the gyromagnetic compass may be either above or below 25 that o! the atmosphere. that is, either positive or negative, the latter being shown herein. In this case. air is continuously exhausted from the gyrocasethrouahpipe Mandaconnectedpump (not shown) andenters the cssethrough several-30 openings for spinning the rotor, providing air Y flow for the bearings. and for operating the follow-up system. Separate channels I5 and I5' are provided to supply the ports Ii and il' for the im named purpose. These channels extend es, v

upwardly through tbe stem 8 and open into annular channels I8 and I1, respectively, inthe stationary bearing housing il enclosing the conical stem I. ,Connected to said channels are pipes Il and2l connected to ports 22 and 23 in 40 a suitable relay device Il, shown as comprising a central movable piston or plate 24, on each side of which is a ilexible diaphragm 25, 15', each oiwhichsealsinaspaceadiacenttheportsl, 2i. Each space or chamber, however, has a 45 bleed2l,2i' tothe atmosphere,sothatairis continuouslybeinsdrawninfthroughthebleeds.A

`channelsandpipesandintotheevacuatedsyro cssingthroughtheports il, il?. Aslongastbe pcrtsareequallycovered,thepressurebehindthe 50 two diaphrasms or bellows remainsequaland the piste '2l centralised. In case, however, one port iscoveredmorethaniheothenthepressureris inthespaceenclosedbythediaphrssmconnected totbeclosedportandtheplatellistoscedtoward 55 the other diaphragm to control the operation of the servomotor 3I-40.

Said plate 24 is shown as secured to an extension 21 projecting from a bracket 28 pivoted on stub shafts 29, 29 in fixed cross pieces 30, so that when said plate is rocked by the bellows, the bracket is also rocked. Within said bracket is rotatably mounted a turbine wheel or impeller 3| continuously spun by air jet 32 about an axis 33 coaxial with the axis of stub shafts 29, 28'. On the shaft 34 of the turbine I have shown a pinion 35 meshing with a large gear 38 mounted on a. shaft 31 journaled in said bracket, which carries at its outer end a friction roller 38. Said roller is normally midway between friction faces 39, 39' of the driven member or clutch 40, so that when the bracket is rocked in one direction or the other, the friction roller is brought onto one or the other of faces 39, 39' -to drive the member 40 inl one direction or the other. acts to turn the follow-up member l0. For this purpose it is shown as having a spiral thread 4I cut in its periphery, which meshes with a spiral' gear 42 secured to member l0 and cone 8 so as to cause the same to follow the sensitive element of the gyroscope.

In order to prevent overrunning and hunting of the follow-up system, I provide an automatic braking device which is applied whenever the servomotor is moved to the ofi position. Said brake is shown as inthe form of a brake shoe 43 biased to the olf position by being Vmounted on a leaf spring 44. For applying the brake, I have shown an expansible metallic bellows or Sylphon 45 which operates as a cylinder and piston by pressing its lower end against the brake shoe and applying the same whenever the bellows is expanded. The bellows is mounted, as shown, inside the evacuated casing and has its interior connected through a pipe 46 with a ported or valve member 41. Said member has two ports 48 and 49 therein which are normally separated, one of said ports being in direct communication with pipe 46 and the other with the outside air through the screened cap 50. The ported under side 5I of the member 41 is shown as curved about the center 52 of a pivoted cooperating valve member 53. Said member has a narrow channel 54 extending parallel to the pivot pin 52 so that when said valve is central, the ports 48 and 49 are connected to the channel 54, thereby admitting atmospheric air into the interior of Sylphon -45 and expanding the same to apply the brake. When, however, the forked carriage 28 is' rocked in either direction by the engagement of the notch 55' in arm 55 secured thereto with the pin 56 on the arm 53' carrying valve 53, the valve 53 is rocked in one direction or the other far enough to move the slot 54 beyond the ports 48 and 49,-thereby cutting off most of the air supply from outside. When this is done. the Sylphon 45 will collapse almost immediately owing to the escape of the air therein into the evacuated chamber through the leak between the valve parts 5| and 53, thereby removing the brake topermit the servomotor to turn the gear 42.

Since this gear is power driven, I may couple any suitable form of transmitter directly thereto. For this purpose I have shown a small shaft 51 extending up from the cone member 8 and coupled to the shaft of an electric transmitter 58, which may be of the A. C. self-synchronous type. The transmitter is shown diagrammatically as driving a plurality of repeater compass cards 59 and 60 through self-synchronous repeater motors 8l' and 62 in the well known manner.

The member 40 A ings shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. In a gyromagnetic compass, the combination with the rotatably mounted vertical ring member, a rotatably mounted bearing member therefor, a differential air ow pick-off device operable upon relative turning of said members, a continuously driven air motor, means driven by said motor for turning said bearing member, and a reversing clutch controlled by said pick-ofi device and between said motor and said bearing member and turning said member in either direction depending upon the direction of relative turning of said members.

. 2. In a remote reading gyroscopic directional device, the combination with the rotatably mounted vertical ring member, a rotatably mounted follow-up member therefor, a differential air flow pick-off deviceoperable upon relative turning of said members, a continuously operated air motor, means driven by said motor for turning said follow-up member, and a reversing clutch controlled by said pick-ofi device and between said motor and said bearing member and turning said member in either direction depending upon the direction of relative turning of said members.

3. In a gyromagnetic compass, the combination with the rotatably mounted vertical ring member, a rotatably mounted bearing member therefor, a differential air ow pick-on device operable upon relative turning of said members, a continuously operated air motor for turning said bearing member, a reversing clutch controlled by said pick-off device and between said motor and said bearing member and turning said member in either direction depending upon the direction of relative turning of said members, a brake for said clutch and means for automatically applying said brake only when power for the motor is disconnected.

4. In a follow-up system for gyroscopic instruments of the air driven type, the combination with the sensitive and follow-up elements, an air flow pick-oil! device operable upon relative turning of said elements, an air driven servomotor for driving said follow-up element including a continuously driven impeller or rotor, and a two way friction clutch, a relay controlled by said pick-off device for operating said clutch to disconnect the drive or drive the follow-up element in either direction, and an air pressure operated brake for the driven element of said clutch interposed in the drive from said motor to said follow-up element and controlled by the presence or absence of differential air pressure from said pick-off device for suppressing hunting.

5. In a gyromagnetic compass, the combination with the rotatably mounted vertical ring member, a rotatably mounted bearing member therefor, a differential air flow pick-ofi` device operated by and upon relative turning of said members, a continuously driven servomotor for turning the bearing member including an impeller wheel, a pinion thereon, a gear at one side of said pinion and driven thereby, a friction member driven from said gear, a frame pivoted on the axis of said impeller and pinion and carrying said gear and friction member, oppositely facing friction discs on each side of said friction member to be drivenv therefrom, expansible means sub1 ect to diierential changes in air pressure from said pick-off device for turning said frame in one direction or the other to cause said friction member to engage and drive said discs in one direction or the other from said friction member, a driving connection between said discs and said bearing member, a spring brake to prevent hunting, said spring being biased to normally engage said friction members, and pneumatic means responsive to pressure flow from .said pick-off device in either direction for releasing 5 said brake.

. MORTIMER F. BATES. 

